[clang-tidy] Update UnusedReturnValueCheck types

[royjacobson]

Summary

Update the types for UnusedReturnValueCheck after D151383.

1. Add std::errc, std:error_condition
2. Remove absl::Status - it's marked as [[nodiscard]] anyway so it's redundant (and might create double warnings) to check it.

[PiotrZSL]

LGTM but update documentation for this check abseil::Status is listed there.

[royjacobson]

Update docs

[PiotrZSL]

clang-tools-extra/docs/clang-tidy/checks/bugprone/unused-return-value.rst

53

should be break into 2 lines, 80 characters limit per line.

clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp

: ClangTidyCheck(Name, Context),
                                    "::shm_open;"
                                    "::shmget;"
                                    "::sigismember;"
                                    "::strcasecmp;"
                                    "::strsignal;"
                                    "::ttyname")),
       CheckedReturnTypes(utils::options::parseStringList(
           Options.get("CheckedReturnTypes", "::std::error_code;"
+                                            "::std::error_condition;"
+                                            "::std::errc;"
                                             "::std::expected;"
-                                            "::boost::system::error_code;"
-                                            "::abseil::Status"))) {}
+                                            "::boost::system::error_code"))) {}
 
 void UnusedReturnValueCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "CheckedFunctions", CheckedFunctions);
   Options.store(Opts, "CheckedReturnTypes",
                 utils::options::serializeStringList(CheckedReturnTypes));
 }
 
 void UnusedReturnValueCheck::registerMatchers(MatchFinder *Finder) {

clang-tools-extra/docs/clang-tidy/checks/bugprone/unused-return-value.rst

.. option:: CheckedFunctions
    - ``std::basic_string::empty()`` and ``std::vector::empty()``. Not using the
      return value often indicates that the programmer confused the function with
      ``clear()``.
 
 .. option:: CheckedReturnTypes
 
    Semicolon-separated list of function return types to check.
    By default the following function return types are checked:
-   `::std::error_code`, `::std::expected`, `::boost::system::error_code`, `::abseil::Status`
+   `::std::error_code`, `::std::error_condition`, `::std::errc`, `::std::expected`, `::boost::system::error_code`
 
 `cert-err33-c <../cert/err33-c.html>`_ is an alias of this check that checks a
 fixed and large set of standard library functions.